<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    #d1 {
      width: 100px;
      height: 100px;
      border: 1px solid red;
      /*向右移动*/
      margin-left: 100px;
      /*向下移动*/
      margin-top: 100px;
      /**/
      margin-bottom: 50px;
      margin-right: 50px;
      /*四个方向同时添加外边距*/
      margin: 50px;
      /*上下赋值，左右赋值*/
      margin: 50px 100px;
      /*外边距实现居中，auto自动*/
      margin: 0 auto;
      /*上右下左顺时针赋值*/
      margin: 10px 20px 30px 40px;
    }
    #d2 {
      width: 100px;
      height: 100px;
      border: 1px solid red;
      margin-top: 50px;
    }
    span{
      border: 1px solid red;
    }
    #s1 {
        margin-right: 50px;
        /*行内边距，上下无效*/
        margin-bottom: 50px;

    }
    #s2 {
        /*左右相邻，彼此添加外边距，左右相加*/
        margin-left: 50px;
    }
    #big{
        width: 200px;
        height: 200px;
        background-color: red;
        overflow: hidden;/*解决子元素粘连问题*/
    }

    #big>div {
        width: 50px;
        height: 50px;
        background-color: green;
        margin-left: 100px;
        /*当元素的上边缘和上级元素的上边缘重叠时,
        给元素添加上外边距会出现粘连显示异常,
        给上级元素添加overflow:hidden解决*/
        margin-top: 100px;
    }



  </style>

</head>
<body>
<div id="big"><div></div></div>
<span id="s1">span1</span><span id="s2">span1</span>


<div id="d1"></div>
<div id="d2"></div>

</body>
</html>